es whose balance was registered by
hair-line indicators, two small metal cages.

Professor Burr stepped over to a row of common cages set along the wall.
There was a small menagerie there, guinea pigs--the martyrs of the
animal kingdom--rabbits, monkeys, and some cats.

* * * * *

The man of science reached in and dragged out a mewing cat, placing it
in the right-hand cage on the strange table. He then obtained a small
monkey and put this animal in the left-hand cage, beside the cat. The
cat, on the right, squatted on its haunches, mewing in pique and looking
up at its tormentor. The monkey, after a quick look around, began to
investigate the upper reaches of its new cage.

Over each of the animals was suspended a fine, curious metallic
armament. For several minutes, while the woman, puzzled at how this
demonstration was to affect the rescue of her condemned son, waited
impatiently, the professor deftly worked at the apparatus, connecting
wires here and there.

"I am ready now," said Burr. "Watch the two animals carefully."

"Yes, yes," she replied, faintly, for she was half afraid.

The great scientist was stooping over, looking at the balances of the
indicators through microscopes.

She saw him reach for his switches, and then a brusk order caused her to
turn her eyes back to the animals, the cat in the right-hand cage, the
monkey at the left.

Both animals screamed in fear, and a sympathetic chorus sounded from the
menagerie, as a long purple spark danced from one gray metal pole to the
other, over the cages on the table.

At first, Mrs. Baker noticed no change. The spark had died, the
professor's voice, unhurried, grave, broke the silence.

"The first part of the experiment is over," he said. "The ego--"

"Oh, heavens!" cried the woman. "You've driven the poor creatures mad!"

* * * * *

She indicated the cat. That animal was clawing at the top bars of its
cage, uttering a bizarre, chattering sound, somewhat like a monkey. The
cat hung from the bars, swinging itself back and forth as on a trapeze,
then reached up and hung by its hind claws.

As for the monkey, it was squatting on the floor of its cage, and it
made a strange sound in its throat, almost a mew, and it hissed several
times at the professor.

"They are not mad," said Burr. "As I was explaining to you, I have
finished the first portion of the experiment. The ego, or personali